Pressure casting machines



June 18, 1957 L. SAIVES 2,795,827

PRESSURE CASTING MACHINES Filed July 28, 1953 /a. E -E. H 4

' .El. 27 V P Z0a 7o 3 21c Isl-il- 71 22c W i W m .i -q- T q INVENTOR.

ATTORNEY PRESSURE CASTING MACHINES Leon Saives, Billancourt, France,assignor to Regie Nationale des Usines Renault, Billancourt, France, andSociete des Hauts Fourneaux et Forges dAllevard, Paris, France, acorporation of the French Republic Application July 28, 1953, SerialNo.370,837

Claims priority, application France August 30, 1952 3 Claims. (Cl.22-68) The invention relates to machines for casting metals and moreespecially ferrous metals under pressure and is concerned withimprovements applied to the moulds, to the ladle cylinder and to therelative arrangement of elements of the machine.

Certain relative arrangements of the main parts forming a pressuremoulding machine and also the arrangement of the joining plane of themould, having particular properties such as the ease with which thearticles produced are made, form the subject of the invention.

The improvements provided by the invention for these machines render itpossible to obviate certain disadvantages which exist at present- (a) Itis desirable to reduce to the maximum extent the distance traveled bythe molten metal between the pouring point and the mould and tofacilitate the evacuation of impurities.

(b) At right angles to the pouring hole, the liquid steel reaching themetal wall of the cylinder causes a partial union of the steel with themetal of the cylinder, which impedes the displacement of the piston.

By using moulds having a flat joint, the internal edges of the moulds atthe level of the joint are rapidly deformed in a permanent mannerbecause of the temperatures which are reached.

(d) Where the moulded articles have considerable differences inthickness, the cooling of the different parts takes place at unequalspeeds, the thick parts being still liquid while the thin parts aresolidified. The result is that the withdrawal is carried out to thedetriment of the thick parts, with the appearance of cavities in thearticles which are known under the name of shrinkage holes.

Novel arrangements in accordance with the invention are shown by way ofnon-limitative example in the accompanying drawing.

Figures 1 to 4 show diagrammatically several relative positions of thehorizontal mould and of the injection cylinder.

Figure 5 shows the refractory lining of a part of the ladle cylinder andthe arrangement of protecting guide bars in a cross-sectional view takenalong the line 55 of Fig. 5A.

Fig. 5A is a longitudinal fragmentary sectional view taken along theline 5A-5A of Fig. 5 and showing in detail the construction of theright-hand portion of the machine shown diagrammatically in Fig. 4.

Figures 6 and 7 shows the arrangement of joints in the moulds.

Figure 8 shows a mould with a staggered joint.

Figure 9 represents a mould with cooling means.

(a) Arrangement of the main parts forming a machine for casting underpressure:

In the arrangement shown in Figure 1, the mould comprises two halfsections 1 and 2: The plane of the joint 3 is horizontal. The injectioncylinder 4 is at the same time a ladle cylinder and contains aninjection piston 6 and a closing piston 5. The injection cylinder 4 isvertically above the mould.

nited States Patent 6 l 2,795,827 Patented June 18, 1957 With such anarrangement, the length of the path of the molten metal is greatlyreduced. On the other hand, the slag which has a tendency to appearremains in the channel.

In the arrangement according to Figure 2, the mould comprises two halfsections In and 2a: The plane of the joint 3a is horizontal. Theinjection cylinder 4a is at the same time a ladle cylinder and containsan injection piston 6a and a closing piston 5a. The injection cylinder4a is disposed horizontally below the mould 1a and 2a. This arrangementrenders it possible to provide an injection cylinder which can be madein two parts and can be opened, this facilitating the cleaning thereof.

By reference to Figure 3, it will be seen that the mould comprises twohalf sections 1b and 2b. The joint plane 3b is horizontal. The cylinder4b, disposed horizontally along the joint plane, serves at the same timeas a ladle cylinder and injection cylinder. The piston 6b is theinjector piston. With such an arrangement, the path of the molten metalis very restricted and the injection cylinder may be arranged to openinto two parts, which facilitates the cleaning thereof.

In the arrangement according to Figure 4, the joint plane 30 of themould consisting of two half sections 10 and 2c is horizontal, and theinjection cylinder 4c is disposed vertically beneath the mould. Theliquid metal is injected by the piston 60. The metal is poured into theladle cylinder 7' and moved by the piston 8. The ladle cylinder may bedesigned so as to open into two parts for facilitating the cleaningthereof.

(b) Protection obtained by refractory half shells lining the injectionor ladle cylinders and ladle guide bars in a pressure casting machine:

In order to avoid deterioration of the ladle cylinder at right angles tothe pouring hole, a refractory lining or Ceramet lining is disposed inthe lower portion of the cylinder at the point of impact of the moltenmetal from the cylinder. On either side of this lining, each of itsupper generatrices has arranged thereon a metal guide bar and thecontact joint is disposed between these bars and the upper steel halfshell. This arrangement avoids the wear which would be produced on theedge of ajoint which is formed of plain refractory material. Figure 5 isa transverse section of such a device applied to the ladle cylinder of amachine in which this cylinder, by way of example, has a horizontalaxis. The ladle cylinder, formed of an upper half shell 11 and a lowerhalf shell 9, is surmounted by the pouring hole 12. Metal guide bars 10protect the edges 16 and 17 of the lower refractory half shell 9supported in the other half 11 of the ladle cylinder. The metal plates10 and 10' are secured to their respective cylinder halves by fasteningmeans such as screws disposed in the screw holes 26 and 27,respectively, the upper plates 10 engaging upper lining 25.

During the casting, the molten metal can obviously not attack therefractory materials and is sufficiently cooled on arriving at rightangles to the metal of the cylinder in order not to be able to cause thepartial fusion of the cylinder.

(0) Mould arrangement intended for casting under pressure with staggeredpoints:

In order to avoid the deterioration, there is employed a specialarrangement of the joint plane of the moulds which is known as astaggered joint."

Figure 6 is a sectional elevation of a mould having a staggered joint(two parts 20 and 21).

Figure 7 shows a modification of the previous arrangement in which theparts are inverted and are designated 20a and 21a, respectively.

Figure 8 shows a mould with a staggered joint (two parts 20b and 21b)for an object having a core 22b.

ice

In the mould having a staggered joint, the metal of the edges issubjected to much smaller thermal stresses. The same mould may thuswithstand a much larger number of operations.

(d) Use of cooling devices in the moulds:

In order to overcome the disadvantages of cooling at difierent speeds inmoulded articles having unequal sections, the invention here has for itsobject the novel application of cooling devices to the casting offerrous metals under pressure, said cooling devices being in the form ofmembers introduced beforehand into the mould and having in this casenovel advantages.

Figure 9 shows by way of example a mould permitting the formation of acasting under pressure with the use of cooling devices. 20c and 21c arethe half sections of the mould and 220 is a cooling core.

The cooling devices may be so designed as to remain embedded in thearticles by providing, for example, a suitable external covering.

As the casting obtained under pressure are extremely smooth, it is easyto withdraw a cooling device from a casting formed under pressure. Thisproperty renders it possible to use the cooling devices as cores andthus to obtain directly, during the casting, holes of any suitable shapecapable of remaining rough cast.

The present invention obviously covers the application of all types ofcooling devices to all forms of castings obtained under pressure fromferrous metals.

I claim:

1. A machine for casting ferrous metals and the like under pressurecomprising, in combination, a verticallyextending injection cylinder anda horizontally-disposed ladle cylinder connected to said injectioncylinder, said ladle cylinder having a casting opening and being formedfrom two semi-cylindrical portions with the lower portion comprisingopposite the casting opening a refractory 4 lining, the joint betweensaid semi-cylindrical cylinder portions being provided by metallic barswhereby said cylinder portions are separated by said bars.

2. A machine for casting ferrous metals and the like under pressurecomprising, in combination, an injection cylinder and a ladle cylindercombined with said injection cylinder in a single body, said body havinga casting opening and being formed from two semi-cylindrical portionswith the lower portion comprising opposite the casting opening arefractory lining, the joint between said semicylindrical cylinderportions being provided by metallic bars whereby said cylinder portionsare separated by said bars.

3. A machine for casting ferrous metals and the like under pressurecomprising, in combination, an injection cylinder and a ladle cylindercombined with said injection cylinder in a single body, said body havinga casting opening and being formed from two semi-cylindrical portionswith the lower portion comprising opposite the casting opening arefractory lining, the joint between said semicylindrical cylinderportions being provided by metallic bars whereby said cylinder portionsare separated by said bars, said machine including a casting mould andsaid body being horizontally disposed and being positioned below thecasting mould and having a removable end in the form of a piston.

References Cited in the file of this patent UNITED STATES PATENTS1,971,652 Haessler Aug. 28, 1934 2,060,224 Lannert Nov. 10, 19362,079,936 Gastrow May 11, 1937 2,137,764 Wagner Nov. 22, 1938 FOREIGNPATENTS 883,056 France Mar. 15, 1943

